A．He is blamed for the depression in the American hat industry.
B．He is a good example that an influential person sets a fashion.
C．He is a typical case showing American changing fashions.
D．He is the only man in America who didn’t wear a hat outdoors.

A．Getting the work done in mixed groups of sizes.
B．Having clear division of labor as a society.
C．Each ant helping with all the tasks.
D．All size groups are ideally suited to their jobs.